Stephen Jay Gould’s monumental The Structure of Evolutionary Theory ‘‘attempts to expand and alter the premises of Darwinism, in order to build an enlarged and distinctive evolutionary theory . . . while remaining within the tradition, and under the logic, of Darwinian argument.’’ The three branches or ‘‘fundamental principles of Darwinian logic’’ are, according to Gould: agency (natural selection acting on individual organisms), efﬁcacy (producing new species adapted to their environments), and scope (accumulation of changes that through geological time yield (...) the living world’s panoply of diversity and morphological complexity). Gould’s efforts to contribute something important to each of these three fundamental components of Darwinian Theory are far from successful. (shrink)

Erect posture and large brain are two of the most significant anatomical traits that distinguish us from nonhuman primates. But humans are also different from chimpanzees and other animals, and no less importantly, in their behavior, both as individuals and socially. Distinctive human behavioral attributes include tool-making and technology; abstract thinking, categorizing, and reasoning; symbolic (creative) language; self-awareness and death-awareness; science, literature, and art; legal codes, ethics and religion; complex social organization and political institutions. These traits may all be said (...) to be components of human culture, a distinctively human mode of adaptation to the environment that is far more versatile and successful than the biological mode. Cultural adaptation is more effective than biological adaptation because its innovations are directed, rather than random mutations; because it can be transmitted "horizontally", rather than only "vertically", to descendants; and because cultural heredity is Lamarckian, rather than Mendelian, so that acquired characteristics can be inherited. I explore ethics as a distinctive human trait. The question whether ethical behavior is biologically determined may refer either to the capacity for ethics (i.e., the proclivity to judge human actions as either right or wrong), or to the moral norms accepted by human beings for guiding their actions. I will propose: (1) that the capacity for ethics is a necessary attribute of human nature; and (2) that moral norms are products of cultural evolution, not of biological evolution. (shrink)

This article seeks to show how several rhetorical tools were used and, in fact, played a central role in the argumentation advanced by Niles Eldredge and Stephen Jay Gould in their 1972 seminal article on the theory of Punctuated Equilibria. It is analyzed how Eldredge and Gould proceeded through three steps that, sequentially integrated, made their argument compelling. It is shown how they made use of analogies, metaphors and other rhetorical tools. It is sustained that they began by priming the (...) reader to distrust the current interpretation of the fossil record offered by most paleontologists and then, in a second step, they used specific visual representations in order to suggest that the competitor theory was committed to the idea of an even and slow evolution at a constant rate, an image utilized by them as straw man. Finally, it is analyzed how, in their third step, Eldredge and Gould made use of several rhetorical arguments to present their theory as new for paleontology while, at the same time, placing it well inside the frame of the modern synthesis, and how they also managed to present their theory as more promising and capable of making predictions for future researches than the competitor theory. (shrink)

We explore the distinctive characteristics of Mexico's society, politics and history that impacted the establishment of genetics in Mexico, as a new disciplinary field that began in the early 20th century and was consolidated and institutionalized in the second half. We identify about three stages in the institutionalization of genetics in Mexico. The first stage can be characterized by Edmundo Taboada, who was the leader of a research program initiated during the Cárdenas government (1934-1940), which was primarily directed towards improving (...) the condition of small Mexican farmers. Taboada is the first Mexican post-graduate investigator in phytotechnology and phytopathology, trained at Cornell University and the University of Minnesota, in 1932 and 1933, respectively. He was the first investigator to teach plant genetics at the National School of Agriculture and wrote the first textbook of general genetics, Genetics Notes, in 1938. Taboada's most important single genetics contribution was the production of "stabilized" corn varieties. The extensive exile of Spanish intellectuals to Mexico, after the end of Spain's Civil War (1936-1939), had a major influence in Mexican science and characterizes the second stage. The three main personalities contributing to Mexican genetics are Federico Bonet de Marco and Bibiano Fernández Osorio Tafall, at the National School of Biological Sciences, and José Luis de la Loma y Oteyza, at the Chapingo Agriculture School. The main contribution of the Spanish exiles to the introduction of genetics in Mexico concerned teaching. They introduced in several universities genetics as a distinctive discipline within the biology curriculum and wrote genetics text books and manuals. The third stage is identified with Alfonso León de Garay, who founded the Genetics and Radiobiology Program in 1960 within the National Commission of Nuclear Energy, which had been founded in 1956. The Genetics and Radiobiology Program rapidly became a disciplinary program, for it embraced research, teaching, and training of academics and technicians. The Mexican Genetics Society, created by de Garay in 1966, and the development of strains and cultures for genetics research were important activities. One of de Garay's key requirements was the compulsory training of the Program's scientists for at least one or two years in the best universities of the United States and Europe. De Garay's role in the development of Mexican genetics was fundamental. His broad vision encompassed the practice of genetics in all its manifestations. (shrink)

William Paley ( Natural Theology , 1802) developed the argument-from-design. The complex structure of the human eye evinces that it was designed by an intelligent Creator. The argument is based on the irreducible complexity ("relation") of multiple interacting parts, all necessary for function. Paley adduces a wealth of biological examples leading to the same conclusion; his knowledge of the biology of his time was profound and extensive. Charles Darwin’s Origin of Species is an extended argument demonstrating that the "design" of (...) organisms can be explained by natural selection. Moreover, the dysfunctions, defects, waste, and cruelty that prevail in the living world are incompatible with a benevolent and omnipotent Creator. They come about by a process that incorporates chance and necessity, mutation and natural selection. In addition to science, there are other ways of knowing, such as art, literature, philosophy, and religion. Matters of value, meaning, and purpose transcend science. (shrink)

Knives, birds' wings, and mountain slopes are used for certain purposes: cutting, flying, and climbing. A bird's wings have in common with knives that they have been 'designed' for the purpose they serve, which purpose accounts for their existence, whereas mountain slopes have come about by geological processes independently of their uses for climbing. A bird's wings differ from a knife in that they have not been designed or produced by any conscious agent; rather, the wings, like the slopes, are (...) outcomes of natural processes without any intentional causation. Evolutionary biologists use teleological language and teleological explanations. I propose that this use is appropriate, because teleological explanations are hypotheses that can be subject to empirical testing. The distinctiveness of teleological hypotheses is that they account for the existence of a feature in terms of the function it serves; for example, wings have evolved and persist because flying is beneficial to birds by increasing their chances of surviving and reproducing. Features of organisms that are explained with teleological hypotheses include structures, such as wings; processes, such as development from egg to adult; and behaviours, such as nest building. A proximate explanation of these features is the function they serve; an ultimate explanation that they all share is their contribution to the reproductive fitness of the organisms. I distinguish several kinds of teleological explanations, such as natural and artificial, as well as bounded and unbounded, some of which but not others apply to biological explanations. (shrink)

This paper sets forth a familiar theme, that science essentially consists of two interdependent episodes, one imaginative, the other critical. Hypotheses and other imaginative conjectures are the initial stage of scientific inquiry because they provide the incentive to seek the truth and a clue as to where to find it. But scientific conjectures must be subject to critical examination and empirical testing. There is a dialogue between the two episodes; observations made to test a hypothesis are the inspiration for new (...) conjectures. Inductive generalizations may also inspire hypotheses, but cannot validate them. A hypothesis is empirically tested by ascertaining whether or not predictions about the world of experience deduced from the hypothesis agree with what is actually observed. This has been appropriately considered the 'criterion of demarcation' that distinguishes science from other knowledge. But scientific hypotheses must satisfy other tests as well, e.g., whether they have explanatory value and further understanding. I briefly explore such issues as verifiability and falsifiability, empirical content and truthfulness, contingency and certainty, fact and theory, error and fraud. Science like any human activity is subject to error and to the foibles and other failings of human beings. But severe attempts of empirical falsification and other trials yield knowledge that stands the test of time and provides a foothold for further knowledge. Moreover, scientists have developed social mechanisms, such as peer review and publication, to evaluate their work. Because the research of scientists depends on the validity of previous knowledge, it is of great consequence that they discern valid from invalid knowledge and thus scientists are inclined to transcend ideology, nationality, friendship, monetary interest and other prejudices when the mettle of scientific knowledge is at stake. I use historical examples to illustrate some relevant aspects of scientific practice: its success (Mendel), misrepresentation (Darwin), ideological abuse (Lysenko), arrogant violation of the requirement of testing (Koch), theory replacement (Priestly and Lavoisier, Newton and Einstein), and the indispensability of context (Oswald Avery and Alfred Wegener). (shrink)

The question whether ethical behavior is biologically determined may refer either to thecapacity for ethics (e.i., the proclivity to judge human actions as either right or wrong), or to the moralnorms accepted by human beings for guiding their actions. My theses are: (1) that the capacity for ethics is a necessary attribute of human nature; and (2) that moral norms are products of cultural evolution, not of biological evolution.Humans exhibits ethical behavior by nature because their biological makeup determines the presence (...) of the three necessary, and jointly sufficient, conditions for ethical behavior: (i) the ability to anticipate the consequences of one's own actions; (ii) the ability to make value judgements; and (iii) the ability to choose between alternative courses of action. Ethical behavior came about in evolution not because it is adaptive in itself, but as a necessary consequece of man's eminent intellectual abilities, which are an attribute directly promoted by natural selection. (shrink)

The theory of punctuated equilibrium has been proposed as a challenge to the modern synthesis of evolutionary theory. Two important issues are raised. The first is scientific: whether morphological change as observed in the paleontological record is essentially always associated with speciation events. This paper argues that there is at present no empirical support for this claim: the alleged evidence is based on a definitional fallacy. The second issue is epistemological: whether macroevolution is an autonomous field of study, independent from (...) microevolutionary knowledge. It is herein argued that macroevolution and microevolution are not decoupled in two senses: identity at the level of events and compatibility of theories. But macroevolution is autonomous in the epistemologically important sense: macroevolutionary theories are not reducible to microevolutionary principles. It is finally pointed out that the discipline of macroevolution is notoriously lacking in theoretical constructs of great import and generality. (shrink)